Pneumatically Stabilized Platforms - PSP
The static float structural system originally proposed by Marshal Savage for the Aquarius marine colony was certainly feasible but not entirely practical and thus presented TMP with a critical logistical catch-22. Static float platform systems cannot be constructed at sea without the establishment of a sheltered water enclosure, thus necessitating the pre-construction of a large breakwater structure for that purpose. This was designed into the overall purpose of the Aquarian colony by having it serve perpetual duty thereafter as a shelter for mass mariculture/algaeculture. But since this breakwater itself was static float based and could not be built at sea, it needed a very large separate coastal facility for this purpose. This took for the form of the Aquarius Rising pre-development phase where a series of dozens of coastal eco-villages would each contribute to the construction of Aquarius through the development of its technologies, production of breakwater modules, OTEC system components, and the establishment of independent shipping capability. Problem was, these dozens of communities all required a very ideal large area coastal lagoon location –some of the rarest, remotest, and most expensive real estate in the world. This presented a catch-22. To create Aquarius one needed to first create a collective facility at least as large as Aquarius and which was far more expensive and time-consuming to create. Thus initiating Aquarius Rising proved to be the single-greatest obstacle facing the nascent First Millennial Foundation organization –a problem that nearly destroyed it. With TMP2 we have devised a simple solution to this catch-22 with the concept of founding Aquarius directly with a small floating community structure that can start at any convenient near-shore location, grow incrementally like any normal town or city, and move progressively father out to sea and toward the Equator according to the scale of its structure and the economy-of-scale of transportation its population can support. What Savage did not know at the time he developed the Aquarius plan was that there were many more options for marine structural systems available on which a structure like the Aquarius colony could be developed; systems far more convenient and sea-worthy than the modular static float. Today, the leading marine platform technology is one called PSP or Pneumatically Stabilized Platform. It is with this simple technology that we attain the ability to build structures of any size at sea without the need for breakwater shelter, thus eliminating the need for an Aquarius Rising phase and affording a floating community structure the ability to expand incrementally and indefinitely. Developed by Float Inc. in the early 1990s, the PSP is a quite simple structure with impressive capabilities. A PSP consists of an array of open-bottom cells like a cluster of overturned drinking glasses with a flat deck built on top. These cells are rigidly connected and linked by air ducts at the top communicating air pressure from one cell to another. As wave fronts pass into the cell array they compress the air in cells like a pneumatic cylinder, increasing the air pressure in the cell ahead of it. In this way the energy in the wave itself is used to attenuate that wave. The result is that a PSP will consume all waves of wavelength shorter than the cross-section profile of the platform. Thus the platform remains as level and stable as if it were standing on a rigid tower in the water, like many oil rigs use, and will function as a breakwater allowing direct docking of vessels on its leeward edges and the deployment of new platform modules from that side, allowing them to be manufactured on the platform. A very neat solution to the problem of platform stability and construction, but the PSP goes even further. It can extract some of that wave energy as electricity by placing small turbines inside the air ducts linking the cells. Thus the platform becomes its own source of power that can be used for its own active station-keeping using electric azimuth thrusters mounted on the platform edge or under some of its cells. (so their drive motors can be kept on-deck for each maintenance) This eliminates the need for anchor cables –which for structures in very deep water can easily become astronomical in cost and complexity. Indeed, the anchor cables for the original Aquarius colony design would have consumed the entire world’s output of Kevlar for years! Of course, if you eliminate the need for anchor cables with active station-keeping you retain the potential free mobility of the whole structure. Thus it becomes possible for the PSP-based structure to be moved anywhere –albeit slowly— and so a colony based on this can relocate as it grows. So many logistical problems solved with just one structural concept! PSPs can be made from any materials commonly used in the marine environment today, though the most economical at the moment of concrete. The original Aquarius scheme called for the use of ‘seacrete’ made by electrolytic sea accretion. We have since realized this technology to be impractical and so now base this on the use of more conventional masonry fabrication using conventional concrete initially, eventually more sophisticated cement alternatives like geopolymers, and eventually Sea Foam which will be discussed in another article. PSPs can also be engineered to support most any scale of structure and what they can’t support static float systems can in combination. Since the PSP completely absorbs waves at a certain cross-section width, it becomes unnecessary to use PSP structure in the deeper inner areas of a large platform structure, allowing slightly cheaper and somewhat higher load-bearing static floats of the same modular form factor to be employed instead. One need only design a construction regime that will insure sheltering of these inner areas by the PSP cells during construction. Active stationkeeping also allows for the fabrication of large component modules in one location and their self-deployment to another location. Thus a colony may build its PSP components in one location on their colony structure and sail them out to another part of it or to other settlements. In this way colonies would easily be able to replicate themselves. The one limitation of the PSP is that, to be seaworthy, any platform structure must be of significant scale and high out of the water. A PSP can absorb any waves of wavelength shorter than its cross-section but waves of height greater than its surface-to-deck height will still wash over the deck. Thus the platforms must be built to suit expected wave heights and may require additional deployable sea wall barriers as a storm defense. This tends to preclude close access to the water for facilities and inhabitants on the structure unless based on the creation of internal lagoons sheltered by the rest of the structure. As we can see in the images in the Aquarius article, TMP2 colony designs are based on that premise, employing radiating internal lagoons for areas of water recreation, mariculture, and shipping. This also tends to make PSPs impractical for the earliest stages of a marine settlement where the structure is already in a sheltered bay location where very simple shallow static floats are sufficient. Transitioning between these two very different scales of platforms will take some clever design. Since PSP technology remains relatively undeveloped and undeployed at large scales, its means of fabrication can be expected to evolve and improve considerably over time and adapt to various systems for surface construction. Experimentation in reinforcement and component interface methods are likely. Currently, the typical concrete PSP cells is a combination of slip-formed components relying on conventional rod and mesh rebar and mechanical connection of major components. The typical base platform is a two-level structure with one deck right atop the cell structure and another above that, creating a largely utility sub-space. Future PSP structures may employ homogenous reinforcement and be fabricated in much larger unit modules composed of many cells and with additional utilities conduits and channels formed-in-place. Typical surface construction is based on either fairly light free-standing structures or conventional commercial building systems matched to the underlying module grid but otherwise relatively independent of it. Future structural systems for the full-scale marine colony may much more closely integrate PSP fabrication with surface structural fabrication in order to improve seaworthiness, increase basic load-bearing capacity, and support larger unified macrostructures. New more sophisticated module interfaces and docking methods are likely, linking integral utilities and employing more contiguious joins. Eventually mechanical adhesive systems might be employed. Future PSPs, their modules featuring station-keeping systems built-in, teleoperated controls, and auto-engaging interfaces, may be practically self-assembling. The advent of SeaFoam is likely to introduce radical changes as well, simplifying the topology of the PSP modules, radically improving their strength-to-weight performance, replacing open volume reserve flotation in intersticial spaces with lower density but otherwise monolithic material, and eliminating differences in cost between PSP modules and static float modules used in the deeper interior areas. PSP construction is likely to become a major industry for the Aquarius phase as the settlements themselves set increasingly compelling examples for what is possible with this technology and the self-mobiliy of these structures affords their global export. Manufacturing islands to order may become as significant an industry as cruise liner construction today. The potential applications for these structures run the gamut from shipping and industrial facilities to military facilities, disaster response to high-value waterfront development, airports to resorts and theme parks and, of course, science and launch facilities. Once well-established, initial settlements may be quite economically self-sustained by their PSP structural production for others, long before they even approach their final equatorial home and deploy complete batteries of OTECs and mariculture facilities. It’s long been said that real estate is the best investment because they aren’t making any more of it. Well, now we can… Parent Topics *Aquarius Supporting Technologies Peer Topics *OTEC *Sea Towers *SeaFoam *Aquarian Digital Infrastructure *VersaBot *Cold Water Radiant Cooling *Large Area Cast Acrylic Structures *Polyspecies Mariculture *Free-Range Fish Farming *Algeaculture *Terra Preta *Cold-Bed Agriculture *Hydroponics *Small Space Animal Husbandry *Tidal/Wave/Current Systems *Algae-Based Biofuel Systems *Vanadium Redox Systems *Hydride Storage Systems *Next-Generation Hydrogen Storage *Alternative Hydrolizer Systems *Supercritical Water Oxidation *Plasma Waste Conversion Phases Category:Aquarius Supporting Technologies Category:Aquarius Supporting Technologies